A disabled man wrongly accused of being a paedophile was murdered and his body torched in a drunken vigilante attack just days after his killer warned police that he would take the law into his own hands, it emerged today.

Lee James, a father of three young girls, repeatedly stamped on the head of Iranian Bijan Ebrahimi then dragged his dead body one hundred yards and set it alight after an escalating witch-hunt against the innocent man that had seen him branded a "paedo" by a mob outside his front door.

The victim filmed his killer storming his house three days before he was killed when James warned that he was going to "f*ck him up" - but it was Mr Ebrahimi who was arrested when police were called to sort out the dispute on a Bristol estate.

After police viewed the footage, Mr Ebrahimi was released from custody to return to his small flat while a crowd rounded on the Iranian who cowered inside his home while he was openly, loudly and falsely accused of child abuse by an "out-of-control" mob, a court was told.

After killing Mr Ebrahimi in the early hours of July 14 this year, James returned to his home and told his partner that his children - aged four, two and one - would be proud of what he had done. "We've got it sorted," he said.

Warning: Video contains content that some might find upsetting

James was jailed for life today for what the judge called an act of "murderous injustice". The 24-year-old killer had wrongly claimed that Mr Ebrahimi had been recording his children and fuelled a campaign against the victim - known locally as Ben - which resulted in his arrest and alienation.

The dead man's family criticised the authorities for failing to protect the vulnerable Mr Ebrahimi who had been burnt out of his previous home during years of racist attacks and harassment.

Police accepted there had been a "collective failure" by the authorities who were meant to have protected Mr Ebrahimi. Twenty-four hours before the attack, Mr Ebrahimi emailed the head of the local police team to say that he did not feel safe at home - but the message was not read until after his death.

Twelve police and civilian staff have been interviewed by investigators over the case of Ebrahimi, who was cleared after a cancer scare only a week before he was murdered. Bristol city council has launched its own investigation and both inquiries are not expected to end until next year.

Mr Ebrahimi had been desperate to leave the home where he had lived for six years and had been recording instances of anti-social behaviour to try to force a move, which included filming James drinking while he was with his children.

Police released a video (above) taken by Mr Ebrahimi days before he was killed, showing James threatening to "f*** him up" if he caught him taking pictures of him again.

James, who had a history of domestic violence, had openly talked of burning his neighbour's house down after he claimed that the 44-year-old had been filming his children with a sexual motive.

James told police that he would "sort it out himself" if they did not act. He told officers that he "wasn't scared of being arrested or going to prison and would do anything to protect his children," said Andrew Langdon, QC, for the prosecution.

Police believe Mr Ebrahimi was killed after he emerged in the early hours when he thought he was safe to water his cherished hanging baskets and was spotted by James. The 24-year-old locked his girlfriend and daughters inside the flat while he launched a brutal attack on the 44-year-old Iranian. A witness watching from a nearby house said that she saw him stamping on Mr Ebrahimi's head in a rage and shouting "have some of that", the court was told.

With another neighbour, Stephen Norley, 25, James dragged the body away and poured white spirit over the body and set it alight. The body was burnt so badly, that it was unrecognisable to an officer who had met him two days earlier.

In a panic, the two men stripped threw away their clothes in an amateurish attempt to hide what they had done.

James returned to the house and told his partner: "We sorted him out for you… tell the girls I did it for them… he's been burnt," Bristol Crown Court heard.

"I bet this is about that fucking paedo," he told officers when he was arrested at his home in Capgrave Crescent, Brislington, Bristol.

During questioning by police, he accepted that he kicked Mr Ebrahimi four or five times "like a football". "I had so much anger in me, I just wanted him to leave my girls alone," he said.

Sentencing him to a minimum of 18 years, Mr Justice Simon told him: "You decided wrongly that he was a paedophile and that this put him outside the law.

"You thought you were entitled to take the law into your own hands. What you did had nothing to do with law or justice…. The law protects life. This was an act of murderous injustice."

The extent of the abuse directed at Mr Ebrahimi emerged as his family revealed he had been trying to move from the area for years. Mr Ebrahimi first came to Britain in 2000, but back problems meant that he was registered disabled.

His family said yesterday that he had been subjected to bullying and racism on a daily basis, causing the quietly spoken Mr Ebrahimi to slip into depression.

His sister said that she had seen him called "foreigner", coakroach and "Paki" and told to go home many times when she visited his flat. The victim spent his time caring for his flowers and a stray cat.

"We hope that nobody else ever has to witness an innocent man being abused, taunted and tortured in the way that Bijan suffered," said his sister Manizhah Moores in a statement. "The question that now must be answered is whether Bijan's death could have been avoided had he been afforded the protection from the authorities he deserved. Lessons must be learned before other vulnerable lives are lost."

The police watchdog, the Independent Police Complaints Commission, said three of the 12 officers had been interviewed under criminal caution because of potential charges against them of misconduct in public office. The three have been suspended.

The watchdog is also investigating reports of earlier contacts with Mr Ebrahimi going back a number of years and how they dealt with other agencies. Nick Gargan, the chief constable of Avon and Somerset police, said: "It is clear that there was a collective failure on the part of statutory agencies and others to protect Mr Ebrahimi."

The video confrontation that led to murder

A video shot by Bijan Ebrahimi that was released today reveals a terrifying glimpse of the abuse he suffered from the neighbour who would eventually kill him.

The footage shows Lee James drinking beer outside Mr Ebrahimi’s home, his child in a pushchair beside him. It then cuts to James confronting the 44-year-old Iranian inside the house. Still holding the can and a cigarette while jabbing his finger into Mr Ebrahimi’s chest, James appears to mock his accent, shouting: “I come to your fucking house – don’t take pictures of me then, all right?” As a woman standing in the doorway tries to pull him away, he goads Mr Ebrahimi to call the police, saying: “How old are you? I’m a little boy.” Mr Ebrahimi tells him to get out but it only provokes James more as he screams: “Take pictures of me again and I’ll fuck you up.”

Mr Ebrahimi did call the police but was himself arrested. He was released and returned home. Three days later he was dead.